The present invention relates to adjustable articulated beds and particularly those having a pivotally-adjustable back support section and a head rest or pillow section adjustably tiltable relative to the back support section.
Adjustable beds have been used for many years to alter the contours of top surfaces of mattresses to thereby controllably adjust the support on the different portions of the bodies of persons lying on them. This support adjustment can be for therapeutic purposes, for comfort reasons, or for the user's convenience, as when the user wants to sit propped up to read, eat or watch television. Originally, this adjustment was by manually-operated mechanical levers or cranks. Later, these manually-operated mechanical devices were replaced by one or more motors which powered the adjustable bed into the desired position through gear trains, chain drives, sprocket drives, and/or threaded shafts.
Adjustable beds are typically used in hospitals or convalescent homes by patients who must spend long periods of time in bed for health, injury or physical handicap reasons. The use of adjustable beds in private homes has increased markedly though in recent years. This is due to the popularity of home television and video viewing, the aging of the population and the technical advances which have been made in the construction, operation and capabilities of adjustable beds. Examples of adjustable beds are shown in U.S. Pat. Nos. 4,381,571 (Elliott), 4,385,410 (Elliott et al.), and 4,407,030 ('030 Elliott), in copending U.S. applications Ser. Nos. 8/213,675 and 08/404,326, and in PCT International Applications PCT/US95/03121 and PCT/US95/03171. Each of these patents, applications and all other patents, publications and applications mentioned anywhere in this disclosure are hereby incorporated by reference in their entireties.
In addition to having the back section of the bed being pivotally adjustable relative to the seat section thereof, it is also often desirable to have the head support section to be pivotally adjustable relative to the back section. By tilting the head support section up and thereby raising the user's head up (relative to his back) he can be more comfortably positioned for reading, eating, watching television or conversing with others. Where the bed is not equipped with a mechanical head tilt, the user has to prop up numerous pillows behind his head, which can be uncomfortable or inconvenient. Where the user has neck, head and/or back problems, "pillow propping" can be cumbersome or even injurious. Thus, a more accurate, controllable and easy head tilt system is desirable. Some prior art articulated adjustable beds having adjustable head sections are shown in U.S. Pat. Nos. 4,349,924 (Zur) ('924) and 4,535,492 (Sebest), Swiss Patent No. 326006 (Korber), and German Patent Nos. G.91.13.757.8 (Franke GmbH & Co. kG) ("German '757") and G.94.12.497.3 (Franke GmbH & Co. kG) ("German '497"). Other adjustable beds having upper adjustable sections are shown in U.S. Pat. Nos. D255,402 (Lundgren), 3,051,965 (Szemplak et al.), 4,258,445 (Zur) and 4,527,298 (Moulton), and German Patent No. 2.031.471 (Schmutz).